BP's attempt to "fish" three pieces of pipe from the blow-our preventer of its runaway Macondo well has not worked and the company is preparing to move forward with removing the blow-out preventer and replacing it with a new one.

The pieces of pipe have settled against the blow-out preventer and the company is unable to retrieve them, National Incident Commander Thad Allen said in a press briefing this morning.

Officials made the decision to stop attempting to fish out the pipe "due to the apparent fragility of the pipe, which keeps breaking off ... and the unknown condition of the blow-out preventer," Allen said.

BP will spend Saturday and Sunday making preparations to remove the blow-out preventer and replace it with one that is current only the development driller two, a drilling rig that had been working on one of the relief wells.

On Monday and Tuesday of next week, BP will remove the capping stack on the well, which will be temporarily stored nearby on the ocean floor. The company then will begin working to remove the blow-out preventer. The replacement blow-out preventer could be in place by Wednesday, Allen said.

The process, however, could be delayed by weather. It could also potentially be delayed if the blow-out preventer can not be removed with ease, he said.

Allen said the new blow-out preventer that will be placed on the Macondo well would be able to withstand the pressure that the well would undergo during the bottom kill operation. The bottom kill operation, which is expected to take place after Labor Day, involves pumping mud and then cement in from the bottom of the well through a relief well. The bottom kill is considered to be the final step in permanently killing the well.